Project Overview
The new nine-story Family Justice Center Courthouse, in Santa Clara, Calif., replaces a mismatched hodgepodge of leased buildings that housed a variety of court services with one beautiful community center. Building this new modern center both improved service offerings and increased the operational efficiencies for county residents, says Mark Piaia principal at ZGF Architects, the designer for this project.
The owners wanted the new building to provide a calming stress-reducing environment for the families that the courthouse serves—but it also had to stay within a tight budget. “As with all projects, cost was a major early consideration and was the primary reason we decided to proceed with precast concrete for the exterior in lieu of travertine stone cladding,” Piaia says. A key benefit of using precast concrete was that the mix design could mimic travertine in color and texture, giving the owners the classical Greek styling they sought with a modern-day price tag.
The design of the façade features alternating bands of solid and void that allude to the fluting of a classical Greek column as it is being unfurled, with narrow curved solid forms between the windows. “The plastic nature of precast concrete, while still being inherently strong and durable, allowed us to create the image of handset radiused travertine stone, while still meeting strict blast requirements,” Piaia says.
The most iconic aspect of the design is the 14-ft state seal of California cast into the west-facing building elevation, which catches the light at sunset, providing a distinctive and attractive icon for the building. “This type of art piece is very challenging, and is only as good as the craftsmanship and skill of your precast contractor,” Piaia says. “The finished, installed state-seal panel looks flawless and the judges love it, especially since it can be seen from the neighboring buildings and the freeway.”
Precast Solution
Though as a courthouse structure, the design had to be more than beautiful. The owners needed a building that is durable, easy to maintain, and able to protect occupants from any blast and sniper assault. “Precast concrete was able to successfully traverse all of these criteria,” says Mark Hildebrand, chief engineer of Willis Construction Company, the precaster on the project.
The design had to provide resistance to large overturning loads for the slender column covers, but the alternating A/B composition of the curtain wall and precast concrete panels made traditional connections insufficient. “The amount of weld required to resist overturning was so significant that, if applied all at once, it would have deformed the structural steel outriggers and pulled the panels out of alignment,” Hildebrand says.
To mitigate these design constraints, his team developed custom connections, based on concepts tested on the shake table at the University of California, San Diego, in which portions of the connection assembly, called ductile fuses, were designed to yield and deform when highly loaded. “The ductile fuse has currently been successfully applied around the entire courthouse to not only allow joint-free, L-shaped corners and minimal panel-to-panel joint sizes, but also significantly improve the precast panel system’s response to blast loading.” |